Novel Nanohybrids Derived from the Attachment of FePt Nanoparticles on Carbon Nanotubes
Φόρτωση...
Ημερομηνία
Συγγραφείς
Tsoufis, T.
Tomou, A.
Gournis, D.
Douvalis, A. P.
Panagiotopoulos, I.
Kooi, B.
Georgakilas, V.
Arfaoui, I.
Bakas, T.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Nanosci Nanotechnol
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Multiwalled carbon nanotubes (MWCNTs) were used as nanotemplates for the dispersion and stabilization of FePt nanoparticles (NPs). Pre-formed capped FePt NPs were connected to the MWCNTs external surface via covalent binding through organic linkers. Free FePt NPs and MWCNTs-FePt hybrids were annealed in vacuum at 700 degrees C in order to achieve the L1(0) ordering of the FePt phase. Both as prepared and annealed samples were characterized and studied using a combination of experimental techniques, such as Raman and Mossbauer spectroscopies, powder X-ray Diffraction (XRD), magnetization and transmittion electron microscopy (TEM) measurements. TEM measurements of the hybrid sample before annealing show that a fine dispersion of NPs along the MWCNTs surface is achieved, while a certain amount of free particles attached to each other in well connected dense assemblies of periodical or non-periodical particle arrangements is also observed. XRD measurements reveal that the FePt phase has the face-centered cubic (fcc) disordered crystal structure in the as prepared samples, which is transformed to the face-centered tetragonal (fct) L1(0) ordered crystal structure after annealing. An increase in the average particle size is observed after annealing, which is higher for the free NPs sample. Superparamagnetic phenomena due to the small FePt particle size are observed in the Mossbauer spectra of the as prepared samples. Mossbauer and magnetization measurements of the MWCNTs-FePt hybrids sample reveal that the part of the FePt particles attached to the MWCNTs surface shows superparamagnetic phenomena at RT even after the annealing process. The hard magnetic L1(0) phase characteristics are evident in the magnetization measurements of both samples after annealing, with the coercivity of the hybrid sample over-scaling that of the free NPs sample by a factor of 1.25.
Περιγραφή
Λέξεις-κλειδιά
carbon nanotubes, magnetic nanoparticles, fept, hybrid materials, transformation, nanocrystals, decoration, mossbauer, catalysts, metal
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000261390800052
http://www.ingentaconnect.com/content/asp/jnn/2008/00000008/00000011/art00052?token=004915908f8086720297d76347770232b2f2424516f2c2b6d3f6a4b4b6e6e42576b642738
http://www.ingentaconnect.com/content/asp/jnn/2008/00000008/00000011/art00052?token=004915908f8086720297d76347770232b2f2424516f2c2b6d3f6a4b4b6e6e42576b642738
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών